The present invention relates to a vaporizer for inhalation and a method for extraction of active ingredients from a crude natural product or other matrix, by means of an ascending airstream heated to the temperature appropriate to volatilize the molecules.
The use of plants as medicinal agents has a long and successful history. The majority of medicines used today are either derived directly from plants or synthesized as variations on natural molecules. However, modern medical practice has, for the most part, abandoned the use of whole plant products because of objections concerning variability in concentration of active ingredients, and unpredictable rates of active drug release from orally ingested crude drugs. Even teas made from medicinal plants cannot fully overcome the latter objection, as the dose provided depends on compound solubility and the conditions of extraction. In addition, accurate self-titration of this dose cannot be expected to overcome either objection, considering the excessive time-lag between oral ingestion and the onset of action.
The best resolution of these problems is through pulmonary ingestion of vaporized compounds, if they are sufficiently volatile. This provides a more immediate means of relief and a more accurate method for dose self-titration, as well as allowing a means for applying compounds to the pulmonary tract itself, as is necessary with diseases such as bronchial asthma, etc. Pulmonary ingestion of drugs also circumvents the xe2x80x9cfirst-pass effectxe2x80x9d by which oral drugs are transferred from the intestines and then partially or entirely metabolized by the liver, before entering the blood stream.
Unfortunately, the only technique available to accomplish pulmonary application of crude natural drugs has been via the method of smoking. This is objectionable from the medical perspective because pyrolysis products are irritating and long-term ingestion of smoke has been implicated in the etiology of various pulmonary disease states (e.g., emphysema, cancer, etc.).
Other objections to inhalers such as U.S. Pat. No. 87,603 (Tichenot) which continuously heats or pyrolizes a substance on a grating, and U.S. Pat. No. 1,858,580 (Collins) which steam heats a carrying agent permeated with a medicated substance, involve the lack of ability to either maximize the extraction exposure of the specimen particles, or to promote a uniform extraction of the aggregate charge through its periodic mixing. Additionally, prevention of large particle inhalation which may prove irritating to the pulmonary system of the user, and providing a demand-only flow of heated gas upon each inhalation, which spares wasteful loss of active ingredient during periods of device disuse, is not achieved.
An object of the present invention is to provide a vaporizer and a method by which a hot gas stream vaporizes and uniformly extracts the active ingredients of a crude natural product or other specimen without pyrolysis, thereby avoiding the potentially detrimental effects of smoking.
A further object of the present invention is to spare the wasteful loss of active ingredients extracted by the vaporizer due to a continuous gas flow instead of a demand-only gas flow, and also to prevent the inhalation of large particles by the user due to a lack of a filtering mechanism.
A still further object of the present invention is to prevent clogging of the vaporizer apparatus due to evaporated compounds condensing on the permeable support structure of the vaporizer apparatus.
Yet another object of the present invention is to initiate a high speed of air flow through the vaporizer, such that lofting of the crude natural product is more easily achieved, in order to maximize the extraction of the active ingredients, without excessive inhalation force.
The present invention extracts volatile active ingredients from a crude natural product, as well as other volatile substances (e.g., essential oils) impregnated into an inert matrix (e.g., paper), by means of a moving airstream heated to the temperature appropriate to volatilize the molecules of the product or substance. Transfer of these agents or ingredients as a water-free aerosol is simultaneously accomplished by this same airstream. In addition, the means of introducing the heated gas into the pulverized crude drug from below provides for the solid particulates to be suspended in the airstream, completely exposing them to the extractive gases, as well as causing a mixing of the aggregate charge upon each inhalation.
In cases where prevention of labile active compound denaturation (e.g., oxidation) is required, the substitution of a stream of hot inert gas (e.g., helium, argon) for the stream of hot air can be implemented. The use of helium carries the additional advantage of raising the voice pitch of the inhaler, reminding the user that air has not been inhaled.
Upon each inhalation, the heated gas is introduced from below and ascends through, in most embodiments, a permeable support structure (e.g., fritted glass disk, etc.), subsequently causing specimen particles to be suspended within the confines of the isolation chamber. This allows a maximized gas extraction exposure for each suspended particle and promotes a uniform extraction of the aggregate charge through its periodic mixing. In addition, this method ensures that the support structure is kept clean and unclogged, since evaporated compounds are constantly swept away from its upper surface. A filter provided downstream from the permeable support structure prevents large particles from being inhaled by the user.
During device disuse in one embodiment, the heated airstream flows through a side-arm of the vaporizer apparatus, preventing wasteful loss of active ingredients. In another embodiment, the side arm can also be used to divert mixed purge gases from the specimen, when the specimen is required to be under the flow of inert gas during its extraction.